All too often, source code spends a lot of time on basic housekeeping, monitoring the state of many objects. This is wasteful, and with C# it is unnecessary. Software expert Stephen Morris shows how C# provides a range of callback mechanisms that obviate the need for polling objects for state information.

"I thought this is why we used the delegate event model, or the event subscriber model, so that we didn't have to monitor all this stuff?"

You are absolutely 100% correct. I have no idea why the author went through all the pains of setting up all the callbacks/polling/whatever you want to call it, by hand in this example when delegates (Name EventHandler delegates) would have more than sufficed, as well as made the code much more readable, and smaller.